The present invention relates to hand tools and more particularly to an adapter coupling device into which a screwdriver is positioned by using one hand and without pulling an outer sleeve for the outer sleeve is automatically moving backward simultaneously with the inserting action of the screwdriver and utilizing the asymptotic line or arc surface principles to force a retaining means (a ball, a cylinder or a W-shaped ring larger than 180° circumference) gripping the screwdriver inside the adapter. When removes the screwdriver from the adapter, pushes the outer sleeve upward and stops it at a positioning place. The screwdriver is although still stayed within the adapter. But the user can pick it up from the adapter freely without moving the outer sleeve downward so as to prevent an inadvertently touching on the outer sleeve that causes the screwdriver breaking-off the adapter.
FIGS. 1 and 2 show “a pneumatic jaw structural improvement” which is a R.O.C. application, serial number 87210259 and comprises an outer sleeve 10 wrapping a large spring 11 and a hollow cylinder 12 inside which is a small spring 13 a cylindrical slider 14 an inner sleeve 15, etc., a C-shaped retaining ring 16 and (an upper cap 17 being used to secure the structure. The lower end of the hollow cylinder 12 has a tang 18 which is provided to connect the structure with a pneumatic machine. The large spring 11 may be in free state or under pressure. The hollow cylinder 12 has a pair of ball receiving slots 151 in opposing peripheries and the cylindrical slider 14 has a magnet 141 in the body for attracting a screwdriver 1. However, this product must move down the outer sleeve 10 preceding to assemble the screwdriver 1 to have the inner wall 101 of the outer sleeve 10 disengaged with the steel balls 102. It is inconvenient because it always need other person helping to finish this job.
FIGS. 3, 4, 5 show a U.S. Pat. No. 5,934,384 which comprises a cylindrical adapter 20 having a hexagon positioning recess 21, an outer sleeve 25 covering the adapter 20, a pair of concaved annular grooves 22 and 23 spacedly formed in outer peripheries. The annular groove 22 is wrapped by an arcuate plate 24 in the middle portion of which is a protruding plate 241 (as shown in FIG. 5) inserting into a through hole 221 of the annular groove 22, a C-shaped ring 231 wrapped in the annular groove 23 and biased by a spring 201 for providing the outer sleeve 25 upward sliding force, the inner wall of the outer sleeve 25 is a slope which is capable of pressing the arcuate plate 24 moving inward to having its protruding plate 241 stop against the rhombic grooves 5 of the shank of the screwdriver 4 which is secured in the adapter 20. When slides the outer sleeve 25 upward, the arcuate plate 24 is disengaged with the inner wall of the outer sleeve 25 and the protruding plate 241 is also disengaged with rhombic grooves 5 so that the screwdriver 4 is free to be removed from the adapter 20. However, the user has to move the outer sleeve 25 upward with one hand preceding to insert the screwdriver 4 into the adapter 20 with other hand that's very inconvenient, too. Further, in order to smoothly engage the protruding plate 241 into the rhombic grooves 5, it must be thinner than the thickness of the arcuate plate 24 so as to add the working steps. Moreover, if the protruding plate 241 is to process not so well, it would never insert into the annular grooves 22 that becomes defective product.
FIG. 6 shows a U.S. Pat. No. 3,767,218 which comprises a cylindrical adapter 30 wrapped with an inward camber sleeve 35 which has a lower end screwed on a lower cap 36, a polygon positioning recess 31 in the top of the adapter 30, a pair of large through holes 32 and a pair of small through holes 33 spacedly and symmetrically formed in the opposing walls of the recess 31 for respectively pressing in a pair of large steel balls 321 and a pair of small steel balls 331, a C-shaped ring 34 stopping against a spring 301 to enable the sleeve 35 elastically moving downward. When the sleeve 35 slides downward, the large and small steel balls 321 and 331 are pressed in to stop against the screwdriver 6 inside the positioning recess 31. When the sleeve 35 moves upward, the steel balls 321 and 331 move outerward to set the screwdriver 6 free and removable from the positioning recess 31. This patent has the same disadvantage that the user has to help by other person to engage or disengage the screwdriver 6 with the positioning recess 31 that's also inconvenient.
FIGS. 7 and 8 show a U.S. Pat. No. 6,311,989 which comprises a cylindrical adapter 40, an outer sleeve 45 having a introrse upper portion 451, a hexagon positioning recess 41 in upper portion of the adapter 40, two through holes 42 and 43 in opposing peripheries of the recess 41 of different heights, a steel ball 421 desposed in the through hole 42, a steel ball 431 in the through hole 43, a retaining ring 44 desposed between the adapter 40 and the sleeve 45 for stopping against a spring 401 so that the sleeve 45 is elastic. When the sleeve 45 slides downward, its introrse upper portion 451 presses the steel ball 421 to enter into an annular groove 3 of a screwdriver 1, the steel ball 431 stopped against an outer periphery of the screwdriver 1. When slides the sleeve 45 upward, its introrse upper portion 451 is no longer stopped against the steel balls 421 and 431 so that the screwdriver 1 is removable. This patent has a disadvantage that the screwdriver must have an annular groove or a notch in periphery, other type of the screwdrivers are unsuitable. If the user puts the box upside down, the screwdriver 1 will automatically breaking-off because it is in the state of removability.
FIG. 9 shows a German Patent No. 102004011579A1 which comprises a cylindrical adapter 50, an outer sleeve 55 having an introrse upper portion wrapped on the adapter 50, a polygonal recess 51 in the top of the adapter 50, a pair of large through holes 52 and a pair of small through holes 53 of different height in opposing peripheries of the recess 51, a retaining ring 54 on an outer periphery of the adapter 50 stopped against a triangular annular convex 502, a spring 501 on lower outer periphery of the adapter 50 for providing electricity to the adapter 50, when slides the sleeve 55 downward, the steel balls 521 and 531 stop against the screwdriver so that the screwdriver 1 is securely positioned in the polygonal recess 51. When slides the sleeve 55 upward, the steel balls 521 and 531 are automatically broke away from the screwdriver 1 which is in the state of removal. This patent has the same disadvantage as the above described prior arts. They all use an outer sleeve of introrse surface or plane surface pressing the steel balls without any change. All of them have same disadvantage of unable to insert the screwdrivers into the positioning recess with one hand and no the function of temporarily keeping the screwdriver stable so that if inadvertently touch or knock the outer sleeve will cause the breaking-off of the screwdriver.
Another R.O.C. Patent No. 92219566, titled “screwdriver box pick up and engagement structure improvement” (as show FIGS. 10 and 11) comprises an axle rod 60, a bushing 61 on the upper periphery, an attracting element 62. The axle rod 60 further has a positioning recess 63 for receiving a screwdriver 4 therein, a slot 64 in a periphery of the positioning recess 63 abutting the bushing 61 which has a ball hole 65 incorporation with the slot 64, a shoulder 671 inside the sleeve 67 stops against the top of the steel ball 66, a spring 68, the bushing 61 and the sleeve 67, an attracting element 62 is composed of a spring 621 and a magnet 622 which positioned in the lower portion of the axle rod 60 and is a element simultaneously having the attaching and elastic function. Whereby, the screwdriver 4 can easily and stably insert into the positioning recess 63 or picking up or change a new one all with one hand. When the screwdriver 4 is inserted into the positioning recess 63, it presses the spring 621 retreated and be attracted by the magnet 622. When the screwdriver 4 releases the spring 621, the spring 68 with resilient force to put the screwdriver 4 slightly out of the positioning recess 63 but still attracted by the magnet 622 for easily to pick up without breaking-off. This patent has an advantage to permit the user to insert the screwdriver 4 into the positioning recess 63 without sliding the sleeve 67 but only the movement of the bushing 61, the spring 68, the ball 66, the magnet 63 and the spring 621. To comparison with the present invention, you can find their apparent difference because the steel balls in the present invention don't move up and down. Besides there is no bushing used in present invention.
Further, a U.S. Pat. No. 7,063,332 (same as the German Patent No. DE10254339 and the R.O.C. Patent No. 92219566) in comparison with the above discussed R.O.C. Patent No. 92219566 (as shown in FIGS. 11 and 12) you will find they are similar in most of the structure. They are utilize a spring means directly stopping against the steel balls and without a bushing. The user although can insert the screwdriver with one hand. The spring means displaces but not the sleeve. When the screwdriver becomes removable it still attracted by the magnet and not breaking-off. In comparison with the R.O.C. Patent No. 92219566, they have the same disadvantages.